Effective Income Tax Rate Reconciliation, Tax Exempt Income and Dividends, Amount

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Effective Income Tax Rate Reconciliation, Tax Exempt Income and Dividends, Percent

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the income tax rates.

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Income Taxes - Statutory Federal Income Tax Expense, Effective Income Tax Expense, Rates (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amount
Statutory Federal Income Tax Expense									$ (138.9)	$ (41.8)	$ (56.4)
Tax-exempt Income and Dividends Received Deduction									4.3	4.8	9.8
Stock-Based Compensation									4.4	1.4	0.4
Nondeductible Executive Compensation									(2.5)	(1.4)	0.0
Tax Reform									0.0	26.4	7.4
Other, Net									2.2	(0.1)	(2.4)
Income Tax Expense	$ (32.2)	$ (32.5)	$ (26.4)	$ (39.4)	$ (1.1)	$ 11.8	$ (8.0)	$ (13.4)	$ (130.5)	$ (10.7)	$ (41.2)
Rate
Statutory Federal Income Tax Expense									21.00%	21.00%	35.00%
Tax-exempt Income and Dividends Received Deduction									(0.70%)	(2.40%)	(6.00%)
Stock-Based Compensation									(0.70%)	(0.70%)	(0.20%)
Nondeductible Executive Compensation									0.40%	0.70%	0.00%
Tax Reform									0.00%	(13.30%)	(4.60%)
Other, Net									(0.30%)	0.10%	1.40%
Effective Income Tax Benefit (Expense) from Continuing Operations									19.70%	5.40%	25.60%